1. Field of the Invention
The present invention relates to coordinate input control in a display-integrated coordinate input apparatus which includes a display having a drawing area and an operation area thereon, and in which drawing and operation instructions are input on the display by using a single coordinate input unit.
2. Description of the Related Art
A display-integrated drawing input apparatus has been known which includes a display unit and a coordinate input mechanism (digitizer). The coordinate input mechanism uses the display unit, whose screen has a drawing area and an operation detecting area (hereinafter referred to as an “operation area”). The operation area is next to the drawing area and functions as operation switches.
When, in the above apparatus, the operation area on a side of the screen is constituted by a plurality of operation switch areas and is realized by an operation input unit identical to that in a digitizer, by mounting electronic components, such as tactile switches and connectors corresponding to various functions, on a printed circuit board, the large cost required to install wiring in the housing of the apparatus by using connecting cords can be saved. Accordingly, the mounting of the electronic components has an advantage in that the operation switch forming cost can be reduced.
In a case in which the screen of the display has the drawing area and the operation area at adjacent positions, as described above, when drawing is performed by means of drawing such as a user's finger or a drawing pen, if the means of drawing mistakenly protrudes from the drawing area into the operation area, it is determined that a switch operation has been designated, thus resulting in an operation mistake.
In addition, in many cases, the display-integrated drawing input apparatus employs a system in which a coordinate input unit of the digitizer emits infrared radiation almost in parallel to the surfaces of the drawing area and the operation area on the display unit and coordinate detection is performed by using infrared radiation reflected by the means of drawing such as the user's finger or drawing pen. In this system, after the means of drawing temporarily loses contact with the drawing area and the operation area, when an intended operation is performed again, a zone in which coordinate detection is performed by using the infrared radiation extends to a relatively broad region positioned away from the drawing area and the operation area. Thus, separation of the means of drawing cannot be detected, so that a state in which intended drawing and operation cannot be performed occurs.